Vehicle for mixing concrete and like materials



April '21, 1936. o. c. BARRYMORE VEHICLE FOR MIXING CONCRETE AND LIKE MATERIALS Filed Feb. 28, 1933 INVENTOR. URSIJN [.BARRYMURE Ma? 8 ATTORNEY Apr-i121, 1936.

o. c. BARRYMORE VEHICLE FOR MIXING CONCRETE AND LIKE MATERIALS Filed Feb. 28, 1933 2 Sheets-Sheet 2 IN VEN TOR.

A TTORNE lil Patented Apr. 21, 1936 U N -lT E D STATE PATENT OFFICE VEHICLE FOR MIXING GQNCRETE AND LIKE MATERIALS- r Orson C. Barrymore, San- Francisco, Calif., as-

1'? Claims.

This invention relates to vehicles for transporting'mixed concrete or for mixing, while in transit, .the ingredients which make up the concrete, the vehicle being particularly adapted for usein connection with'centrallylocated plants wherein'the various ingredients aref'stored. In such' plants, the ingredients are first measured, as by weighing, and are then charged into the mixer; If there be a mixer at the plant, the concrete may be prepared there and then transferred to the vehicle in which it is kept agitated whilein transit. When the'concrete is to be prepared while in transit, the measured, butunmixed, ingredients, with the proper amount of water, are introduced into the mixing drum of the vehicle. The mixing is accomplished by rotatinglthe drum, which may be efiected by gearing the drumto the engine-which propels the vehicle, but preferably by gearing it to a separate engine or motor on the vehicle. The ingredients, of course, fill the lower parts of the drum, and the latter is so constructed interiorly that rotation of the same in one direction on its horizontal axis moves the outermost portions of the mixture forwardly. while the portions nearer the axis move rearwardly. When the direction of rotation of the drum is reversed, the outermost portions of the mixture move to the rear. The specific means for effecting theseresults will be described in detail hereinafter and the purpose in view in reversing the rotation of the drum-will be set forth.

AsfarasIam aware,- all vehicles for transporting concrete, whether previously mixed or mixed while in transit, have discharged their contents through a gate-controlled orifice at the rear end of the mixing drum.- These gates and their operating mechanisms add materially to the initial cost'of the vehicle. Moreover, the gates stick in use, wear" and get loose, fail to prevent leakage andarealways troublesome. Some vehicles tip the drum upwardly about its rear end'to pour the concrete out through the orifice. Since the drum -with its contents is quite heavy, aspecial hoisting mechanism is required for this purpose,

and" such mechanism is not only costly, but is heavy: andadds-materially to the weight to be transported;

One of the'objects of my invention is to provide" means for discharging the contents of the drum without the use of a gate or without tipping. This is eflected by providing a permanently opendischarge orifice at the axial center of the rear. end of thedrum, with meansfor elevating themixture to this orifice through which it flows.

Other objects of the invention will appear in the following specification and claims.

The accompanying drawings illustrate a vehicle which embodies my invention in the form whichl now prefer. However, it is realized that the details shown and described may be varied more or less Widely without departing from the principles of my invention, and it is to be understood that his my purpose to claim the invention. broadly except in such claims as are spe cifically limited in terms to structural details.

In the accompanying drawings, Fig. 1 is a side elevation of a vehicle which embodies my invention, a portionof the drum being broken away; Fig. 2 shows a section taken on the line 22' of Fig. 1 and looking towardthe rear, the rear axles and wheels being omitted; Fig. 3 is a rear elevation, from which the axles and wheels and also the pivoted distributing chute are omitted; Fig.

4 isaside elevation on an enlarged scale of the rear endofthe chassis frame, the mixing drum and'distributingchute, parts being broken away; Fig. 5 is a plan view showing, more or less diagrammatically, .the enginefor rotating the mixing drum andthe train of gearing, including the transmission for reversing the direction of rotation of the drum; Fig. dis a sectional view taken onthe line 66 of Fig. 2; Fig. '7 is asectional view. taken axially through the rear end of the water-pipe within the drum; Fig. 8 is adetailed sectional'viewtaken on line 88 of Fig. 3; Fig. 9 is a vertical sectional view taken just inside the rear head of the drum, as on line 9-9 of Fig. 4, and showing the elevating plate for the concrete when in one position; Fig..10 is a sectional view taken through the drum on line l0'-l0 of Fig. 9; Fig. 11 is a view similar to Fig. 9 but showing the positionof the elevating plate after the drum has been givensomething more than three-quarters of a rotation; Fig. 12 is a view similar to Fig. but taken on line I2-I2 of Fig. 11; Fig. 13 is a view similar to Figs. 9 and 11 but showing the elevating plate turned to a different position; Fig. 14 is-a view similar to Figs. 10 and 12 but taken on line l4-I4 of Fig. 13; Fig. 15 is'a view similar'toFigs. 9, 11 and 13 but showing a pair of elevating plates; Fig. 16 shows the same parts as Fig. 15 but rotated into another position; Fig. 1'7 is a rear view of the diaphragm or partition plate which separates the mixing and discharging chambers of the mixing drum when a single elevating plate is used, as in Fig. 9; Fig. 18 is a similar view of the diaphragm which is used with a pair of elevating plates, as inFig. 15; Fig. 19 is a sectionalview taken on line I9-l9 of Figs. 11

and 12, and Fig. 20 is a perspective view showing a detail.

Turning first to Fig. l, 20 designates the front and the rear wheels of a vehicle, such as a sixwheeled truck, the vehicle being propelled by a suitable motor within the hood 22 in front of the cab 23. 24 represents the side members of the chassis frame, upon which are supported pairs of anti-friction rollers 25, best seen in Fig. 3. These rollers, in turn, support the mixing drum 26, which is provided with encircling tracks 21, one for each pair of rollers 25. As shown, there are two of these tracks; but obviously, additional tracks may be employed if desired. These tracks rest upon their respective pairs of rollers and roll thereon as the drum is rotated about a horizontal axis. The tracks, which are preferably T-shaped in crosssection, are held upon the rollers by stationary members 28 which engage over the flanges of the rails, the said members being in pairs and in opposed relation, as shown on Figs. 4 and 8. The members 28 prevent tipping of the drum; for, as will be shown, the contents of the drum are discharged without tipping the latter. The drum is preferably of uniform diameter except that it is tapered inwardly at its front end, as shown at 29, for a purpose hereinafter explained. The front end of the drum is completely closed, while the rear end is provided with a central orifice 30 which is surrounded by a rearwardly extending and outwardly flaring flange 3|, as best seen in Fig. 19. At any suitable point, preferably in its cylindrical wall, the drum is provided with a filling opening which is normally closed by a cover 32.

As stated, the drum may be rotated by the motor which propels the vehicle along the road, but I prefer to use a separate and independently controlled motor for that purpose. This motor may be of any suitable type, but I have shown and prefer to use an internal combustion engine, as indicated conventionally at 33 in Figs. 2 and 5, the same having a radiator 34. a clutch 34a, a transmission gear-casing 35 with shifting lever 36 and a train of reduction gearing connecting the engine with a pinion 3'! which meshes with a large annular gear 38 at the forward end of the drum. The train of gearing referred to may be of any suitable design and arrangement, and the transmission gearing within the casing 35 is similar to or identical with the transmission gearing commonly used in automotive vehicles, so that further illustration and description of these parts are deemed unnecessary. It is to be understood, however, that the reversing feature of the transmission gearing is important, since it is through it that the direction of rotation of the mixing drum is reversed; but the specific gearing for accomplishing this result is conventional and, in itself, forms no part of my invention. By turning the pinion 3'! first in one direction and then in the other, the reversal of rotation of the drum is effected, as will be understood.

The interior of the drum is divided transversely by a partition plate or diaphragm 39, the same having, in the form first to be described, a single arc-shaped notch or opening, 40, therethrough just inside the outer wall of the drum. As will be noted from Figs. 1 and 19, this diaphragm is relatively near the rear end of the drum, so that the latter is divided into a large forward chamber 4| and a relatively small chamber 42. Since the ingredients are mixed in the chamber 4 I the same is herein termed the mixing chamber. The chamber 42 is termed the discharging chamber,

since the mixture is discharged therefrom through the orifice 3!].

Attached tothe inner cylindrical wall of the drum and extending helically about the same Within the mixing chamber 4| are vanes 43. These project inwardly only part way toward the drum axis. Of course, they turn with the drum and, in so doing, push the ingredients toward one or the other end of the drum, depending upon the direction of rotation of the latter. At the same time, the vanes lift the materials up more or less and force them out into the mass again, by which action, repeated over and over, the ingredients arethoroughly mixed. The mass of ingredients normally fills the drum well above the axial line or to a depth which is greater than the width of the vanes. While, therefore, that part of the mass which is in position to be engaged by the vanes is moved positively by the screw-like action of the latter, that part which is nearer the axis of the drum and not contacted by the vanes moves in the reverse direction with the result that the mass is moved backwardly and forwardly, being tumbled about by the action of the vanes, and is thus thoroughly mixed and kept ready for instant use.

The tapered forward end of the drum prevents the accumulation of the materials at the outer edges of the front drum head and guides the m..- terials as they reverse their direction of flow. For more thoroughly mixing the ingredients, the mixing chamber is provided with short auxiliary vanes 44 set obliquely within the spaces between the vanes 43. As many of these auxiliary vanes are employed as may be found desirable. The

rear ends of the vanes 43 are welded or otherwise secured to the front face of the diaphragm and are further strengthened by triangular plates which extend from the inner edges of the vanes to the diaphragm, one of he same being shown at 45 in Figs. 19 and 20.. These plates 45 serve not only to strengthen the connection between the vanes and diaphragm but to prevent the materials from settling down and tending to compact directly in front of the opening in the diaphragm, it being noted from Fig. 20 that the plate t5 extends from the inner edge of said opening to the van... The materials, being in a semi-liquid condition, do not fiow freely and but little of them will pass through said opening when the drum so rotating as to cause the vanes to move the materials forwardly.

When, however, the lever 36 of the transmission gearing is thrown into reverse and the drum is oppositely rotated, the mixture is forced rearwardly by the vanes 43, through the opening 49 in the diaphragm and into the discharging chamber 42. This operation will be clear fro-m a consideration of Fig. 10. When the drum is rotating in this reverse direction, that vane 43, which terminates at the right-hand end of the opening 40, cams or pushes the concrete through the said opening.

Within the discharging chamber and extending helically from the left-hand end of the opening 40 to the rear head 25a of the drum is a short vane 46, between which and the adjacent vane 43 the materials are forced. Concentric with the drum and spaced therefrom a distance approximately equal to the width of the discharge chamber is a ribbon-like guide plate 41, the same being a short but complete cylinder except for a gap between the points designated 47a and 411) where it is cut away, for a purpose hereinafter set forth. This guide plate extends across the discharge chamber, being secured at its front and rear edges tothe diaphragm 39 and the rear head 26a, respectively, as shown in Fig. 19. At the point All), the guide plate is attached to the elevating plate 48. This plate is attached to the inner curved surface of the drum and is extended spirally therefrom until it reaches a point 48a where it becomes concentric with the drum. It terminates at 48?). Its rear edge is attached to the drum-head 26a and its forward edge is attached to the diaphragm 39 except where it contacts the short vane 6 to whichit is attached, as shown in 10. That part of the elevating plate 48 between the points and 58b is attached to the drum-head just outside the discharge opening 30, as indicated in Fig. 19. From the point 48?) the end of the elevating plate is unattached but is extended diagonally across the discharging chamber '52 to a point 5-9 where it is attached to the diaphragm 39. That part of the elevating plate which is embraced within the points 48a, A81) and 49 is unattached to the diaphragm except at the point 4-9, while the points 48a and 48b and all the rear-edge of the plate between the latter points are attached to the head 26a just outside the discharge opening 38. Consequently, a space, designated 50, is provided between the said unattached part of the elevatingplate and the diaphragm.

For supplying water to the ingredients within the drum, a pipe 5| is provided at the axis of the drum and is extended through the front head of the latterto and through the diaphragm 39, terminati in the discharging chamber and'within the space 59, as shown in Fig. 19. The water is discharged into a perforated member 52, which forms a sort of sprinkling head. The space between the guide plate il and the elevating plate @8- is closed by a member 53 to prevent the water and any solid materials from entering the .narrow and tapered space below the member, asviewed in Fig 11. The water entering the space settles down to and rests upon the spiral elevating plate 48; it will be understood, however, that the water is supplied only when the ingredients are being mixed, at which time the parts shown in Figs. 9 to 14: are turning anti-clockwise. Consequently, the water flows outwardly on the elevating plate and accumulates in the bottom of the discharging chamber until the opening 49 in the diaphragm approaches lowermost position when the accumulated water begins to flow into the mixing chamber. As the drum continues to rotate anti-ciockwse the water remaining in the discharging chamber is lifted by the short vane 45 and is directed by it to and through the opening it? untii it has all entered the'mixing chamber. This flow of the water washes back into the mixing chamber any of the solid substances which may have entered the discharging chamber.

The water for the pipe 5i is supplied from a suitable tank which is preferably located in an elevated position as respects the said pipe so that the water may how by gravity. As shown, the tank is a closed drum atthe rear of the cab 23 and between it and the mixing drum, its axis being horizontal and transverse to the vehicle frame. The water drum is divided by a partition 55 into relatively large and small chambers, 5t and 5?, respectively, and the level of the water in the chamber 55 is indicated by a water-gage 58. It is the water from this chamber that is mixed with the other ingredients to form the concrete, and the gageenables the operator to supply the proper amount for any mixture. The water is fed into the chambers of the-drum't l through openings at 59 and 69, ladde'r'sfil being providedto enable the operator to reach these openings as well as the filling open-- ing 32for the mixing chamber. As will be noted from Figs. 2 and 6, the water passes mm the bottom of the drum chamber 55 through pipe 62, an L-fitting, t3 and pipe 64 into the forward end of the pipe iii of the mixing drum. Since the latter pipe turns while the pipe 54 is stationary, a rotary and leak-proof joint between these pipes must be provided. Any suitable arrangement of parts may be provided. shown, the pipe 6t enters the end of pipe 5i, and a stationary member 65' surrounds bolth pipes, packing glands 66 and 6'! being provided for preventing leakage of the water. For controlling the flow of the water, a valve 68 is interposed-in the pipe 62, said valve being connected through a link t8 with an operating lever H! which is located adjacent the water-gage 58 in order. that the operator may control the valve in ccordance with the indications of the gage.

The water in the smaller chamber 5! of the water drum is intended primarily for flushing out the mixing drum. It is connected with the L- fltting 53 by a pipe ll having a valve l2 therein. When this valve is opened the water passes into the pipe 5'! of the mixing drum to flush the latter as it is rotated.

As the mixed contents of the drum 25 pass outwardly through the orifice 30 and downwardly over the short flange (it, they first contact a stationary guide spout l3 which extends about the lower part of said flange and behind the outer edge thereof, as shown in Figs. 3 and 4. Below the guide spout and in the plane which extends vertically through the center of the mixing drum is a hinge M in a supporting arm 15 for the distributing chute it. This chute is inclined downwardlyand rearwardly, and it has its upper end flared outwardly to extend below and about the guide spout 13. Since the hinge I4 is located centrally below the front edge of this spout, the chute may be swung from side to side to distribute the concrete. For compactness and convenience, the chute is made in two parts hinged together, so that the lower part, 15a, may be turned upwardly and backwardly to lie upon the part 16, as shown in full lines in Fig. 4.

Thus far, the description has applied to a structure in-which the diaphragm 39'has a single aperture 49'; When so constructed, a batch of concrete will be discharged at each rotation of the drum. If a more rapid and regular discharge be desired, a diaphragm like that shown at 39a in Fig. 18 may be substituted, said diaphragm havingtwo diametrically opposed apertures lila therein, each at the rear end of a vane 43. With such an arrangement, two batches of the mixture willbe delivered to the discharging chamber at each rotation of the drum. This will necessitate a pair of spiral elevating plates similar to that shown at 48. In Figs. 15 and 16, I have shown two such plates, the same being designated 48a. To'accommodate both plates, the guide plate 4le is cut away at two diametrically opposed parts forming gaps through which the elevating plates pass. The latter plates are like the plate. 41 except that they diverge from the drum wall at a steeper angle.

Briefly described, and on the assumption that the measured but unmixed ingredients have been charged into the drum at 32, both chambers of In that the water drum have been filled to the desired level, and the materials are to be mixed in the mixing drum 26 while the vehicle is in transit, the operation is as followsz-The transmission lever 36 is moved to turn the drum anti-clockwise, as viewed in Figs. 3 and 9, the clutch at 34a is engaged and the valve 58 is opened to admit water to the drum, the amount of water being measured on the gage 58. The ingredients within the drum will nowbe thoroughly mixed, as has been described. Upon arrival at the place when the mixture is to be used, the vehicle is so positioned that the chute 16'l6a leads to the place where the mixture is to be deposited. Then the lever 36 is moved to cause the drum to turn reversely, or in a clockwise direction as viewed in Fig. 9. A quantity or batch of the mixture will be pushed rearwardly through the aperture 40 in the diaphragm and will occupy the lower part of the discharging chamber, as indicated at A in Fig. 9, it being understood that the greater part of this quantity is hidden in that view by the short vane 46. As the drum rotates, this quantity or batch will be cut off when the aperture has risen at the left of the drum to or above the level of the mixture therein, and will remain in the bottom of the discharging chamber until the elevating plate 48 approaches the position shown in Fig. 11 when it is lifted or scooped up by said plate, as is indicated at A in Fig. 11. Further rotation of the drum lifts the batch to the position indicated at A in Fig. 13, which is at or above the lower edge of the discharge orifice 30, so that the mixture runs out to the distributing spout. In the meanwhile, the drum has made something more than a complete rotation and another quantity or batch of the material has accumulated in the bottom of the discharging chamber, as shown at B in Fig. 13. Continuous rotation of the drum thus segregates, elevates and discharges batch after batch until the entire contents of the drum has been discharged.

When the species shown in Figs. 15 and 16 is used, a batch C is segregated in the discharging chamber and, in substantially a half rotation, is lifted by the plate 480. to the discharge orifice, and by the time the drum has turned to the position shown in Fig. 16, substantially all the batch has been discharged, as indicated at C In the meanwhile, and in the same rotation, another batch, D, has entered the discharging chamber, to be elevated and discharged in the same manner. By this construction, therefore, the batches are discharged with twice the frequency as in the structure of Fig. 9.

I claim.

1. A mixer for concrete and like materials comprising a drum adapted for rotation about its horizontal axis, said drum having a discharge orifice at the center of its rear end, a diaphragm dividing the drum into a relatively large mixing chamber and a relatively small discharging chamber, said diaphragm having an aperture therethrough connecting said two chambers, mechanism for rotating said drum, said mechanism including means for reversing the direction of rotation of the drum, vanes attached to the inner cylindrical wall of the drum within the mixing chamber and extending helically thereabout, one of said vanes extending across in front of said aperture in the diaphragm and being attached to the latter at the edge of the aperture, whereby when the drum rotates in one direction for mixing, the contents of the mixing chamber are moved away from the aperture but when the drum is reversed the mixed contents are moved through said aperture and into the discharging chamber, means through which water for the mixture is fed into the discharging chamber to pass forwardly through said aperture and into the mixing chamber as the drum is turned in mixing, and an elevating plate attached at its outer end to the inner cylindrical wall of the discharging chamber and extended spirally from said wall for gathering up the mixed contents fed into the discharging chamber and elevating them to cause them to be discharged through the discharge orifice, said elevating plate being operative while the drum is rotated in the reverse direction.

2. A mixer as set forth in claim 1 in which the drum is provided with a water pipe at its axial center, said pipe extending forwardly through and beyond the front head of the drum and rearwardly through the diaphragm so as to terminate within the discharging chamber, and means connected with the forward end of said pipe for supplying water thereto.

3. A mixer as set forth in claim 1 in which the elevating plate within the discharging chamber is attached at its rear edge throughout its entire length to the rear head of the drum and is attached at its front edge to the diaphragm, its inner terminal edge being unattached and passing diagonally across the discharging chamber to form a space between the elevating plate and diaphragm in which the water pipe terminates and into which it discharges, for the pur pose specified.

4. A mixer as set forth in claim 1 in which the elevating plate within the discharging chamber is attached at its rear edge throughout its entire length to the rear head of the drum and is attached at its front edge to the diaphragm, its inner terminal edge being unattached and passing diagonally across the discharging chamber to form a space between the elevating plate and diaphragm in which the water pipe terminates, and a spraying head surrounding the end of the pipe within said space, for the purpose specified.

5. A mixer as set forth in claim 1 in which the elevating plate extends spirally from the end which is attached to the cylindrical wall of the discharging chamber to the discharging orifice and then curves about said orifice, said plate being attached throughout its length to the rear drum head.

6. A mixer as set forth in claim 1 in which the mixing chamber is provided with a plurality of auxiliary mixing vanes, said auxiliary vanes being attached tothe outer cylindrical wall of the mixing chamber and extended diagonally in the spaces between the first mentioned vanes.

'7. A mixer for concrete and like materials comprising a drum having a discharge orifice in the center of its rear end, mechanism for rotating said drum, said mechanism including means for reversing the direction of rotation of the drum, a diaphragm dividing the interior of the drum into a relatively large mixing chamber and a relatively small discharging chamber, the diaphragm having an aperture at its outer edge, c

vanes attached to the inner cylindrical wall of the mixing chamber and extending helically thereabout, one of said vanes extending across in front of the aperture in the diaphragm and being attached to the latter at one edge of the aperture, a short vane within the discharging chamber, said short vane being attached to the diaphragm at the opposite edge of the aperture so that the aperture is between the rear end of. the vane in the mixing chamber and the front end of the short vane in the discharging cham-' ber, whereby, when the drum is rotated in one direction, the contents of the mixing chamber are mixed and are moved forwardly from in front of the said aperture and when the rotation of the drum is reversed the mixed contents are moved rearwardly and through the said aperture, and means with-in the discharging chamber for elevating the mixed contents thereof to the discharge orifice in the end or the drum.

8. A mixing device comprising a vehicle, a drum rotatably mounted on said vehicle, said drum having a permanently open discharge orifice at the center of one of its ends, mechanism mounted on the vehicle for rotating the drum, said mechanism including means for reversing the direction of rotation of the drum, a diaphragm dividing the interior of the drum into a relatively large mixing chamber and a relatively small discharging chamber, the end of the drum having the discharge orifice forming one side of the discharging chamber, vanes attached to the inner cylindrical wall of the mixing chamber and extending helically thereabout, said vanes being attached at one of their ends to the diaphragm and the diaphragm having an aperture therein at one side of the place of attachment of the vane thereto, the construction being such that when the drum is rotated in one direction, the contents of the mixing chamber are mixed and are moved away from the aperture in the diaphragm and when the drum is rotated in the opposite direction the mixed contents of the mixing chamber are moved through said aperture and into the discharging chamber, a container for water mounted on the vehicle, a water pipe extending axially into the mixing drum from that end that is opposite the discharging orifice, valved connections between said container and said water pipe whereby measured quantities of water may be introduced into the drum, an elevating plate attached at one of its ends to the inner cylindrical wall of the discharging chamber and extended spirally from said wall to the discharge orifice, whereby the mixed contents of the discharging chamber are elevated to a position to pass out through said orifice as the drum is rotated in its reversed direction, and means mounted on the vehicle for receiving the discharged mixture and directing it to the place where it is to be used.

9. A device as set forth in claim 8 in which the water pipe extends axially through that end of the drum which is opposite the discharge orifice, through the mixing chamber and through the diaphragm, whereby the water enters the discharging chamber and flows therefrom through the aperture in the diaphragm to the mixing chamber.

10. A device as set forth in claim 8 in which the diaphragm is provided with a plurality of apertures and in which the discharging chamber is provided with an elevating plate for each of said apertures.

11. A mixer for concrete and like materials comprising a drum, a diaphragm dividing the interior of the drum into a mixing chamber and a discharging chamber, said diaphragm having an aperture adjacent its outer edge connecting the chambers within the drum, a normally closed filling opening in the wall of the mixing chamber, a discharge orifice in the outer end wall of the discharging chamber at and about the axis of said end, vanes connected to the inner circumferential wall of the mixing chamber and extending helically from the said diaphragm toward the front end of the drum, said vanes operating to move the contents of the drum ran wardly and to mix them as the drum rotates in one direction, and to move them rearwardly through the aperture in the diaphragm and into the discharging chamber when the drum rotates reversely, an elevating plate attached at its outer end to the circumferential wall of the dischargin'g chamber and extending spirally within that chamber to the discharging orifice, said plate serving to elevate the mixed concrete and to cause it to discharge through the discharge orifice when the drum is rotated in a reverse direction from that employed in mixing, means for rotating the drum and reversing its direction of rotation, and means for feeding water to the mixing chamber in measured quantities while the drum is rotating.

12. A mixer as set forth in claim 11 in which the drum is mounted upon a truck and in which the truck is provided with a pivoted chute through which the discharge mixture is delivered.

13. A mixer for concrete and like materials comprising a drum having a filling opening and a discharge orifice, means for rotating the drum and for reversing its direction of rotation, a diaphragm dividing the interior of the drum into a relatively large and relatively small chamber, said diaphragm having an aperture in its outer edge, means within the larger chamber of the drum for mixing the materials therein as the drum is rotated in one direction, said latter means feeding the mixed materials through the aperture in the diaphragm and into the smaller chamber as the drum is rotated in the reverse direction, means within the said smaller chamber for elevating the mixed materials to and causing them to be discharged through the discharged orifice as the drum is thus reversely rotated, and means for delivering water into the larger chamber as may be required during the mixing operation, said means comprising a pipe extending axially through the front end of the drum and through the diaphragm, whereby the water for the mixture is first discharged into the smaller chamber and is caused to flow therefrom through the aperture in the diaphragm into the larger chamber while the drum is rotating in the direction for mixing.

14. A mixer for concrete and like materials comprising a drum having a filling opening and discharge orifice, means for rotating the drum and for reversing its direction of rotation, a diaphragm dividing the interior of the drum into a relatively large and relatively small chamber, said diaphragm having an aperture in its outer edge, means within the larger chamber for mixing the contents as the drum is rotated in one direction, said latter means being adapted to feed the mixed materials through the aperture in the diaphragm and into the smaller chamber as the drum is rotated in the reverse direction, means within the smaller chamber for elevating the mixed materials to and causing them to be discharged through the discharge orifice as the drum is reversely rotated, such means comprising a plurality of lifting plates attached at their outer ends to the circumferential wall of the smaller chamber and extending spirally within that chamber to the discharge orifice, whereby successive charges of mixed materials are raised to and deliveredithrough the orifice, and means delivering water into the larger chamber during the mixing operation.

15.An apparatus as set forth in claim 14 in which the means for delivering the Water comprises a pipe extending axially through the front end of the drum and through the diaphragm, whereby the water is first discharged into the smaller chamber and thence through the aperture in the diaphragm into the larger chamber while the drum is rotating.

16. An apparatus as set forth in claim 14 in which the drum is mounted upon a truck and in which the truck is furnished with a pivoted chute through which the discharge mixture is delivered.

17. An apparatus for mixing and maintaining concrete or like materials in mixed plastic condition, comprising a rotatable drum, a partition extending transversely within the drum and dividing the drum into chambers of unequal volume, said partition having a non-central aperture therein through which intercommunication is established between said chambers along the inner periphery of said drum, said drum having a charging opening through a wall of the larger chamber and a discharge orifice communicating with the smaller chamber and positioned coaxially with the rotation axis of the drum, plasticmixture conditioning means attached to the periphery of said drum within said larger chamber, said conditioning means preventing mixture egress through said non-central aperture when the drum is rotating in one direction and assisting egress through said aperture when the drum is rotating in the opposite direction, and means Within the smaller chamber for picking up the mixture and delivering it to the discharge orifice whereby it is ejected from the drum through said orifice.

ORSON C. BARRYMORE. 

